Improvement in the manufacture of superphosphate of liwe



(might one.

CAMPBELL MORFIT, or sUnBnooK PARK, ENGLAND.

Letters Patent No. 111,370, dated January 31, 1871.

IMPROVEMENT m THEMANUFACTURE or SUPERPHOSPHATE or urns.

fire Schedule referred to in these Letters Iatent and melting past of the same.

To all whom it may concern:

Be it known that I, CAMPBELL MOREIT, chemist, of the city of Baltimore, in the State of Maryland and United States of America, but now at Sudbrook I Park, county of Surrey, England, have invented anew 'and Improved'Method for Making Superphosphate of Lime; and I do hereby declare that the following is a full and exact description thereof.

My invention consists in the chemical treatment of animal or mineral phosphates of lime, without regard to the amountof carbonate of lime which they may contain, for their conversion into iii-phosphate of lime, either pure or associated with sulphate of lime and ammonium or potassium chlorides.

. wood or stone, fitted. with a stirrer, is to be provided,

and charged with Jcommercial hydrochloric acid ofspeciiic gravity 1.170, to. the: extent. of two pounds for every per cent. ofi carbonate of lime which the crude phosphatetmay contain, assuming that South Carolina phosphate or coprol es'are to be operatedupon, and that they contain/respectively, twelve per cent. of carbonate of lime and fifty-five per cent. of til-phosphate of lime, or tnereabont; then, for every ton of either one of those raw materials, there will be required: five hundred weight of hydrochloric acid of specific gravity 1.170. v

The crude phosphate must bc'iu fine powder and allowed to fall into the acid very gradually from a hopper during constant stirring.

As the mass thickens it is to cold water from time to time. When all the crude mineral has been added and stirred into a complete mixture, the whole is .to be left at repose for eight or ten hours. At the end of that period all or nearlyall of the carbonate of lime will havebeen decomposed and dissolved into chloride, of calcium.

This'solution -of chloride oflcaleium is now to be allowed-to drain oil into a separate vat, after which the solid residue is to be washed with several relays of water and the wash-waters mixed with the previous strong liquor. t

The united liquors in the separate. vat are to be treated apart, as will be explained directly.

To the solid residue in the first vat brown oil of vitriol of specific gravity L'dil is to be. added in a very be diluted with hot or thin stream.

the mass is to bcrouscd by stirring for ten to'iiftecn minutes every hour, the whole of thephosphate of lime will have become converted into bi-phosphate and sulphate of lime. 1

The action of the hydrochloric acid preliminary to that of the sulphuric acid and its dilute state keeps down the proportion of fluoride of calcium and oxides and phosphates of aluminum and iron, which otherwise might be dissolved,

Moreover, the use-of hydrochloric acid in this manner gives the advantageof introducing, subsequently, chloride of ammonium or potassium, by chemical interaction, into the fertilizer, thus increasing the potency and profit of the latter, and correcting at the same time all tendency to humidity, which the presence of chloride of calcium would promote.

If only an ordinary commercial supc'rphosphate of high strength is required, then the. sand and otherv insoluble matters of the crude phosphate material may be allowed to remain in the fertilizer and the whole dried for market.

' But should it be required to make pure bi-phospha-te of lime free ii'omsulphate and carbonate of lime, sand,

and other-insoluble matters, the mass, after being freed from the chloride of calcium liquor and treated with brown oil of vitrioL-as above, is to he thinned with warm water, well stirred, and then put into drainingboxes.

Here the contained liquor, holding in solution biphosphate of lime with traces of sulphate, is allowed to drain oil, after which fresh relays of water are to be poured on several times, until all the iii-phosphate of lime has been displaced from the nearly insoluble sulphate ot'lime.

The first liquor passing through together with the subsequent wash-waters is .to be unitedand evaporated in a properlymcnstructed pan or kiln to as great a density as possible. 7 -Atthis stage s'uihcient of finely-powdered mineral "phosphate of lime to dry the whole is to be added, and when the well-stirred mass has become coolit is to be dashed into a fine powder bya Howel or other mill.

The residual sulphate of lime and other. matters in i tbedraining boxcs will be a most excellent mixingmaterial for low grades of fertilizers, after it may have been dric'd in air-currents or a moderately-heatedapartment- I v To economize the hydrochloric acid employed in the preliminary treatment of the crude phosphate the liquor andwash-watcrs which were reservcdiu' a separate vat arc nowto be treated with a dense aqueous 1 solution. of either sulphate of ammonia or' sulphate of potassa l'during constant stirring untila precipitate ceases to be produced.

'lhechloridc'of calcium formed from the carbonate of lime is thus converted into chloride of ammonium or chloride of potassium, while sulphate of lime results simultaneously, there being,' a double exchange of bases "between the two; salts in this reaction.

The choice of. the" ammonia or potassa sulphate must depend upon the application'for which the fertilizer may be intended.

The two salts may he even employed together for the same product, in half portions consecutively, so as to produce a mixtureot' ammonium and potassium chlorides when a compound fertilizer is required.

Crude ammoniacal substituted for the sulphates, and in ,manner as just explained; hut in such cases the lime salt produced would be carbonate insead of sulphate.

The alkaline liquor, or rather solution of ammonium or potassium chloride, is to be drawn oil from'thc precipitated sulphate or carbonate of lime, as the case may be, evaporated to dryness, and mixed with the. bi-phosphate of lime as previouly dried, or sent into market separately.

Ii nor or earlash ma he Claim.

What I claim is Hydrochloric acid, sulphuric acid, sulphate of ammonia or crude ammouiacal liquor, and sulphate or carbonate of potassa, in the treatment of bones, honeash, bone-black, phosphorite, apatite, cooporite or N,

vaza guano, Sombrero guano, South Carolina phosphate, ooprolites, and the mineral phosphates of lime generally, for the economical production of bi-phosphate of lime in a concentrated form, either .with or .without the association of ammonia or potassa salts, after the manner and by the means as herein substantially set forth and described.

In witness whereof I have hcreun to set my hand and seal this twenty-fourth day of August, in the year of our Lord one thousand eight hundred and seventy.

Witnesses:

'1. W. Falcon, 1*. W. ATKINSON. 

